Tanaka K, Nishiura I, Koyama T
No Shinkei Geka. 1987 Jan;15(1):89-93.
A 58-year-old female was admitted because of lumbago and dysesthesia on the lateral aspect of the left leg. She had myelographies and spinal operations 4 years ago. Metrizamide myelogram on admission revealed the findings of adhesive arachnoiditis. During operation, four plaques involving the cauda equina were found, removed and histologically proved to be osseous tissue. In reviewing the previously published cases of arachnoiditis ossificans, it is divided into two forms. One is incidentally found in the arachnoid membrane at the time of an autopsy or spinal operation. The other is a progressive form causing impairment of the spinal cord and cauda equina. Compared with the former, the latter is extremely rare. At present, there appears to be a general agreement about the pathological process to ossification in the latter. The ossified plaque has its origin in meningothelial cell clumps located at the junction of the arachnoid sheet and the trabecula. The ossification occurs secondarily as a result of degenerative change in these clumps after myelography, spinal operation, subarachnoid hemorrhage, spinal trauma and spinal anesthesia. In our case, it is presumed that repeated spinal operations or myelographies played a role as a trigger toward ossification.
一名58岁女性因腰痛及左腿外侧感觉异常入院。她4年前曾接受脊髓造影检查及脊柱手术。入院时的甲泛葡胺脊髓造影显示为粘连性蛛网膜炎。手术中发现4个累及马尾的斑块，予以切除，组织学检查证实为骨组织。回顾既往发表的骨化性蛛网膜炎病例，可分为两种类型。一种是在尸检或脊柱手术时偶然发现于蛛网膜。另一种是进行性类型，可导致脊髓和马尾功能障碍。与前者相比，后者极为罕见。目前，对于后者骨化的病理过程似乎已达成普遍共识。骨化斑块起源于位于蛛网膜片与小梁交界处的脑膜上皮细胞团。在脊髓造影、脊柱手术、蛛网膜下腔出血、脊柱创伤及脊髓麻醉后，这些细胞团发生退行性改变，继而发生骨化。在我们的病例中，推测反复的脊柱手术或脊髓造影检查是骨化的触发因素。
